Ruby on rails ExecJS:：ProgramError:意外标记：名称（选项）

我的应用程序在本地环境下运行良好。我正试图将一个构建推送到heroku。我的命令是：

bundle install
git add .
git commit -am "abcdef"
git push heroku master

然后我遇到了一个关于资产的问题：预编译

remote: -----> Preparing app for Rails asset pipeline
remote:        Running: rake assets:precompile
remote:        I, [2016-01-04T08:32:35.471098 #1018]  INFO -- : Writing /tmp/build_5d68c6d2f7845ca719a5f77705a12798/public/assets/recruiters-e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855.js
remote:        I, [2016-01-04T08:32:35.471825 #1018]  INFO -- : Writing /tmp/build_5d68c6d2f7845ca719a5f77705a12798/public/assets/recruiters-e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855.js.gz
remote:        I, [2016-01-04T08:32:35.477826 #1018]  INFO -- : Writing /tmp/build_5d68c6d2f7845ca719a5f77705a12798/public/assets/recruiters-e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855.css
remote:        I, [2016-01-04T08:32:35.477974 #1018]  INFO -- : Writing /tmp/build_5d68c6d2f7845ca719a5f77705a12798/public/assets/recruiters-e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855.css.gz
remote:        I, [2016-01-04T08:32:35.575303 #1018]  INFO -- : Writing /tmp/build_5d68c6d2f7845ca719a5f77705a12798/public/assets/events-e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855.js
remote:        I, [2016-01-04T08:32:35.575465 #1018]  INFO -- : Writing /tmp/build_5d68c6d2f7845ca719a5f77705a12798/public/assets/events-e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855.js.gz
remote:        I, [2016-01-04T08:32:35.623887 #1018]  INFO -- : Writing /tmp/build_5d68c6d2f7845ca719a5f77705a12798/public/assets/events-31e95c603f03e300e73e01cd6ee747799da57b4d12924aa979e0fa0749681cca.css
remote:        I, [2016-01-04T08:32:35.624406 #1018]  INFO -- : Writing /tmp/build_5d68c6d2f7845ca719a5f77705a12798/public/assets/events-31e95c603f03e300e73e01cd6ee747799da57b4d12924aa979e0fa0749681cca.css.gz
remote:        rake aborted!
remote:        ExecJS::ProgramError: Unexpected token: name (option) (line: 242, col: 14, pos: 7159)
remote:        Error
remote:        at new JS_Parse_Error (/tmp/execjs20160104-1018-1ens1gjjs:2659:11936)
remote:        at js_error (/tmp/execjs20160104-1018-1ens1gjjs:2659:12155)
remote:        at croak (/tmp/execjs20160104-1018-1ens1gjjs:2659:20622)
remote:        at token_error (/tmp/execjs20160104-1018-1ens1gjjs:2659:20759)
remote:        at unexpected (/tmp/execjs20160104-1018-1ens1gjjs:2659:20847)
remote:        at semicolon (/tmp/execjs20160104-1018-1ens1gjjs:2659:21320)
remote:        at simple_statement (/tmp/execjs20160104-1018-1ens1gjjs:2659:24179)
remote:        at /tmp/execjs20160104-1018-1ens1gjjs:2659:22152
remote:        at /tmp/execjs20160104-1018-1ens1gjjs:2659:21493
remote:        at block_ (/tmp/execjs20160104-1018-1ens1gjjs:2659:26198)new JS_Parse_Error ((execjs):2659:11936)
remote:        js_error ((execjs):2659:12155)
remote:        croak ((execjs):2659:20622)
remote:        token_error ((execjs):2659:20759)
remote:        unexpected ((execjs):2659:20847)
remote:        semicolon ((execjs):2659:21320)
remote:        simple_statement ((execjs):2659:24179)
remote:        (execjs):2659:22152
remote:        (execjs):2659:21493
remote:        block_ ((execjs):2659:26198)

注意，我已经编译了特定于控制器的资产（见下文）。我不知道这是否会引起问题

views/layout/application.html.erb

<%= stylesheet_link_tag "application", params[:controller], :media => "all", 'data-turbolinks-track' => true %>
<%= javascript_include_tag 'application', params[:controller], 'data-turbolinks-track' => true %>

# Compile controller assets
%w( recruiters events forms candidates ).each do |controller|
  Rails.application.config.assets.precompile += ["#{controller}.js", "#{controller}.css"]
end

有什么想法或建议吗

更新 我找到了问题的来源。虽然我不确定是什么地方出了问题，也不知道为什么它在本地运行良好

 238        if (fieldClass.match(/(select|checkbox-group|radio-group)/)) {
 239          previewData.values = [];
 240  
 241          $('.sortable-options li', field).each(function() {
 242            let option = {};
      ==============^
      SyntaxError: missing ; before statement
 243            option.selected = $('.select-option', $(this)).is(':checked');
 244            option.value = $('.option-value', $(this)).val();
 245            option.label = $('.option-label', $(this)).val();
 246  
 247            previewData.values.push(option);
 248          });
 249        }

---

通过更新js语法，我能够解决问题，并且资产预编译成功

原创

let option = {};

已更新

var option = {};

---

在我的例子中，资产编译在生产环境中是成功的，但是在登台时，它给出了上述错误。所以我在生产和登台上检查了nodejs版本。在生产上是v12.10.0，在登台时是v10.XX.XX。因此，我在登台时将nodejs版本更新为v12.10.0，它现在正在工作。

由于以下代码而出现类似错误：

debugger

var conversion={}

在

调试器

之后没有分号，尽管有一行新行。知道为什么会发生这种情况吗，因为原始代码是有效的JS？

let

是ES6语法。